Dual offset rudder system

ABSTRACT

A dual rudder system for small, propeller driven boats consisting of two transversely spaced rudder blades mounted in close proximity to and on opposite sides of a boat propeller, with blade portions adopted to pivot about the propeller, and a single control including a control arm connected to each rudder shaft which in turn are interconnected by an adjustable link member and one of the rudder arms has secured thereto a tiller arm for varying the effective rudder angles and positions with respect to the longitudinal axis of the boat and the propeller. The rudders are connected to the boat by a pair of rudder shafts, each carrying an offset bracket, which in turn is connected to its respective rudder so that the rudder shafts can be closely spaced without interfering with the propeller.

United States Patent 1 Duryea [451 Mar. 25, 1975 DUAL OFFSET RUDDER SYSTEM [76] Inventor: Charles S. Dun-yea, 168 N. Bridge St., Somerville, NJ. 08876 [22] Filed: Feb. 7, 1974 [21] Appl. No.: 440,535

Related US. Application Data [63] Continuation-in-part of Ser, No. 298,863, Oct. 19, 1972, Pat. No. 3,828,713, which is a continuation-in-part of Ser. No. 113,247, Feb. 8, 1971, Pat. No. 3,710,749.

Primary Evaminer-Trygve M. Blix Assistant Evaminer-Sherman D. Basinger Attorney, Agent, or Firm-Harold L. Stowell 57 I ABSTRACT A dual rudder system for small, propeller driven boats consisting of two transversely spaced rudder blades mounted in close proximity to and on opposite sides of a boat propeller, with blade portions adopted to pivot about the propeller, and a single control including a control arm connected to each rudder shaft which in turn are interconnected by an adjustable link member and one of the rudder arms has secured thereto a tiller arm for varying the effective rudder angles and positions with respect to the longitudinal axis of the boat and the propeller. The rudders are connected to the boat by a pair of rudder shafts, each carrying an offset bracket, which in turn is connected to its respective rudder so that the rudder shafts can be closely spaced without interfering with the propeller.

1 Claim, 6 Drawing Figures DUAL OFFSET RUDDER SYSTEM This'application is a continuation-in-part of my application Ser. No. 298,863 filed Oct. 19, 1972, now U.S. Pat. No. 3,828,713 which is a continuation-in-part of application Ser. No. 113,247 filed Feb. 8, 1971 and now U.S. Pat. No. 3,710,749.

BACKGROUND OF THE INVENTION l-leretofore flanking rudder constructions and systems have been used, but in most instances complex space consuming mounting and control mechanisms were required, and efficiency of operation was less than optimum. The functions and use of flanking rudders are well known and it is the purpose of the present invention to provide improvements in structure, operation and mounting of such rudders.

SUMMARY OF THE INVENTION It is accordingly a principal object of the present invention to provide a dual rudder system for propeller driven, relatively small boats to improve operational characteristics, with simplified control mechanism and simplicity of mounting. In obtaining these improvements, the rudder blades are mounted in close proximity to and on opposite sides of the propeller to effectively coact with propeller flow and boat hull design for optimum boat control. In one embodiment the blades are mounted on independent rudder shafts and connected thereto by offset brackets and the angular positions of these rudders can be readily varied for propeller torque compensation.

Additional objects and advantages of the invention will be more readily apparent from the following detailed discussion of the preferred embodiments thereof when taken together with the accompanying drawings in which: v

FIG. 1 is a fragmentary side view of a boat having mounted thereon the improved rudder system of the invention with the near rudder broken away to show the relationship between the dual rudders and the propeller;

FIG. 2 is a fragmentary sectional view on line 22 of FIG. 1;

FIG. 3 is a section on line 3-3 of FIG. 2;

FIG. 4 is an enlarged fragmentary perspective view of a portion of the structures shown in FIG. 2;

FIG. 5 is a top plan view of the slip connection between the rudder shafts and the top stabilizing member; and

FIG. 6 is an enlarged exploded view of one of the connections between the rudder control links.

Referring now in detail to the drawings, the stern of a boat hull 10 has operatively mounted thereon a dual offset rudder system 12 in accordance with the invention, including opposed flanking rudder blades 14 and 16 respectively mounted in close proximity to and on opposite sides of propeller 18. The blades as shown are flat, although, as to be more fully described hereinafter, the shape can be varied.

The propeller l8 is'mounted on drive shaft 20 which passes through a conventional external shaft bearing 22 and internally of the boat the shaft 20 is connected to a motor via a transmission not shown.

The dual rudders l4 and 16 are supported respectively from vertical rudder shafts 24 and 26. The rudder shafts pass through a lower backing plate 27, the bottom of the boat 28 and a filler block 30 constructed of 2 wood, metal or plastic, thence through suitable bearing block assemblies 32 and 34 respectively which function to permit rotative movement of the shafts 24 and 26 and provide the fluid seal for the shafts as is well known in the art.

The lower backing plate 27 is connected, through the bottom of the boat, to the filler block 30 by rivets or bolts as shown.

Further, the assembly may include an upper bearing plate 31 which is bored to receive and maintained on the pair of shafts 24 and 26 by screws 33 and races 35 cut in the external surface of each of the shafts. Where desired, the screws 33 may abut against a ball to thereby reduce friction in the assembly.

From the foregoing it will be-seen that a very stable, but simple, assembly is provided.

It will be noted from FIGS. 2 and 3 that the shafts are in lateral alignment with the boats propeller l8 and are spaced a distance A less than the: diameter of the propeller 18 designated D in FIG. 2. This relatively close spacing of the pair of shafts 24 and 26 has particular advantages on non-flat bottomed watercraft wherein a substantial spacing would create installation and alignment difficulties and problems.

The lower end of shaft 24 has secured thereto, such as by welding, a rudder bracket 38. The opposite end of the rudder bracket 38 is secured to the upper inner edge of rudder 14, whereby rotation of shaft 24 causes the bracket 38 to pivot which in turn pivots the rudder 14 in an arc about the propeller 18 as shown in broken line B, FIG. 3 of the drawing from which it will be noted that very close control is obtainable with theioffset bracket 38 and its counterpart 40 for rudder 16 greatly improving the maneuverability of the boat. In the pre ferred construction of the invention the offset brackets have lengths less than the radius of the propeller and the rudders are spaced within the diameter of the propeller.

In order to bring about mutual control of both of the rudder blades 14 and 16, the upper end of each of the rudder shafts 24 and 26 has secured thereto a lever arm 42 for shaft 24 and 44 for shaft 26. Preferably the arms 42 and 44 are connected to the mid-points of the shafts 24 and 26 such that the longitudinal axis of the arms are parallel to the longitudinal axes'of their respective rudders 14 and 16 so that the boats controller can, by viewing the position of the arms 42 and 44, accurately determine the position of the depending rudders. The extended ends of lever arms 42 and 44 are interconnected by an adjustable link member 46 via pivotal connection 48 for shaft 42 and 50 for shaft 44.

Length adjustment of the arm 46 is accomplished by.

having the link member 46 split and telescopically threaded into a connector 52 as shown more clearly in FIG. 4. The adjustability of the link member 46 is provided so that one of the rudders 14 or 16 may be angled in respect to the other to assist in compensating for torque or non-uniform fluid flow about the boat's hull due to the direction of rotation of the propeller. If, for example, rudder 14 is angled slightly in respect to rudder 16 then it is preferable that the lever arm 42 be also adjustably secured to the upper end of its rudder shaft 24, whereby the operator of the boat will find the indicators showing both rudders functioning in unison even though one of the rudders is slightly displaced from the plane of the other to compensate for fluid flow, torque and the like.

In order to complete the assembly, one of the shafts 24 or 26 has secured thereto a tiller arm which in the illustrated form of the invention comprises arm 60 secured to rudder shaft 26. The rudder arm may include means such as illustrated at 62 having connections to the boat controller whereby the pair of rudders may be manipulated remotely from the stern of the boat as is well known in the art.

It will be appreciated by those skilled in the art that while rudder blades 14 and 16 have been shown in the drawings as planar sheet members, the rudder blades may have curvilinear surfaces in the front to rear and top to bottom or both directions to improve fluid flow thereabout. Further, as disclosed in my prior applications, the blades 14 and 16 may be attached to their respective offset brackets 38 and 40 so that their lower ends slope toward or away from the center line of the boat. Further, various modifications may be made in the specific forms of the structures without departing from the scope of the present invention.

From the foregoing description, it will be recognized that the aims and objects of the present invention are fully accomplished and by means of the assembly hereinbefore set forth permits the use of paired flanking rudders which will turn on a smaller radius and stay .closer to the propeller adding substantially to the effect of the rudders and also permitting the use of smaller rudder blades. Further, the use of the offset arms 38 and 40 permits the propeller to operate between the rudder posts which in certain instances permits assembly of the dual rudder system on boats with a minimum of alteration such as the need for dropping of the propeller shaft, etc. Further, it will be seen that through the inter-connecting linkage very simple control is provided without the need for ball joints and the like as employed on certain of the assemblies of my prior inventions.

1 claim:

1. Dual offset rudder system for a propeller driven boat consisting of:

a. a pair of generally vertically disposed rudder shafts rotatably mounted at the stem end of a boat on opposite sides of boats propeller and in lateral alignment with the circleof revolution of the propeller;

b. an offset bracket secured to the lower end of each rudder shaft and positioned tonormally extend toward the side of the boat and away from the propeller;

c. a rudder blade secured to each of said offset brackets;

d. a lever arm mounted adjacent the upper end of each of said pair of shafts with said lever arms positioned to extend in parallel planes when the boat is normally operating along a straight path;

e. link means pivotally inter-connecting the extended end of each of the said lever arms; and

f. means connected to one of said shafts for controlling the angular adjustment of said pair or rudder blades;

wherein the length of each of the offset brackets is less than the radius of the propeller and the rudder shafts are spaced within the diameter of the propeller. 

1. Dual offset rudder system for a propeller driven boat consisting of: a. a pair of generally vertically disposed rudder shafts rotatably mounted at the stern end of a boat on opposite sides of boat''s propeller and in lateral alignment with the circle of revolution of the propeller; b. an offset bracket secured to the lower end of each rudder shaft and positioned to normally extend toward the side of the boat and away from the propeller; c. a rudder blade secured to each of said offset brackets; d. a lever arm mounted adjacent the upper end of each of said pair of shafts with said lever arms positioned to extend in parallel planes when the boat is normally operating along a straight path; e. link means pivotally inter-connecting the extended end of each of the said lever arms; and f. means connected to one of said shafts for controlling the angular adjustment of said pair or rudder blades; wherein the length of each of the offset brackets is less than the radius of the propeller and the rudder shafts are spaced within the diameter of the propeller. 